英文關鍵字
acetylene
autogen
burn
burning
craftsmanship
cuts
cutting
danger
dismantling
energy
fire
flame
flash
gas
hand
heat
hot
industry
instrument
iron
job
metal
moving
occupation
oxyacetylene
oxygen
propane
rail
recycling
seam
spark
sparkle
steel
technology
weld
welder
welding
work
workplace